(a) Field of the Invention
The present invention relates to a system and a method for controlling a hybrid vehicle, and more particularly, to a system and a method for controlling a hybrid vehicle capable of optimizing fuel consumption in the whole region of a designated driving path.
(b) Description of the Related Art
A hybrid electric vehicle may be variously formed using at least two power sources configured of an engine and a motor. The hybrid electric vehicle includes a transmission mounted electric device (TMED) type power train in which a motor, a transmission, and a driving shaft are connected in series. Further, an engine clutch is disposed between the engine and the motor, and thus the hybrid electric vehicle may be driven in an electric vehicle (EV) mode or a hybrid electric vehicle (HEV) mode based on whether the engine clutch is coupled.
The EV mode is a mode in which a vehicle is driven by a driving torque of the motor and the HEV mode is a mode in which the vehicle is driven by a driving torque of the motor and the engine. Therefore, when the hybrid electric vehicle is being driven, the engine may be turned on or off. When a high voltage battery is applied to the TMED type power train, the engine may be turned off in the EV mode. Particularly, the engine may be turned on or off by setting an optimum operating point of the engine. In other words, battery use should be optimized by the hybrid vehicle to maximize improvement in fuel consumption of the hybrid vehicle.
For example, a control of the current hybrid vehicle maximizes system efficiency based on instant driving conditions (e.g., local optimization) and predicts the expected driving conditions and uses the predicted driving conditions to more efficiently use battery energy. In other words, the existing hybrid vehicle control is performed in consideration of the instant driving conditions due to a limitation of operation performance of a controller, a lack of road traffic information, etc. However, the performance of the controller is rapidly improved and the amount and precision of the road traffic information are also increased, and as a result predicting future driving conditions and positively utilizing the predicted driving conditions may be realized.
As an example, a method for controlling a hybrid vehicle improves fuel efficiency by generating a targeted profile when destination information is input under a constant speed drive condition and improves fuel efficiency by applying an optimization technology in a section in which the vehicle is driven in an HEV mode to improve the SOC. As another example, the method for controlling a hybrid vehicle applies a real-time optimization technique at the time of auto cruise driving to extract an optimum fuel efficiency speed profile and then adjust a targeted cruise speed of a vehicle.
The method for controlling a hybrid vehicle is operated by continuously repeating charging and discharging of a battery under congestion driving conditions. In particular, EV mode driving may not sufficiently be implemented due to energy shortage of the battery in a low speed congestion section and the engine should be operated in a low efficiency region to charge the battery.
The above information disclosed in this section is merely for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.